Sun the most efficient energy source

Nuku‘alofa – Solar power is the most efficient renewable energy method in Tonga, students from the University of Canterbury in New Zealand found after investigating various renewable energy projects during a one-week trip.

Five final year electrical engineer students and their supervisor from the University’s Department of Electrical and Computer Engineering have left Tonga after assisting Tonga Power Ltd to investigate various renewable energy projects.

Supervisor Dr Andrew Lapthorn said the most novel approach they observed sought is to produce biofuel from coconuts which, although technically possible, was determined by students as not economically viable for electricity generation.

The different renewable energy options the students investigated including wind power, tidal energy and solar power.

The students modelled various schemes for the islands of Ha‘apai, Vava‘u and Tongatapu which they presented to representatives from Tonga Power.

The students looked at various storage options as well as gauging how much energy each different option could produce.

“The most efficient method is solar power and the students were able to help make recommendations about size and location of panels as part of the University’s continuing relationship with Tonga Power,” Dr Lapthorn said.

Dr Lapthorn said Tonga is vastly different from New Zealand in terms of the resources available.

“People look at renewable energy and they think things like wind and solar and there’s abundance of that in the Pacific but there are challenges such as how to store electricity for use when it is not windy or sunny,” he said.

Diversifying energy sources became an even greater priority for Tonga after cyclone Ian struck Ha’apai where it affected more than 80 per cent of the infrastructure including the power system supplied by two 186kW diesel generators.

The students findings will help Tonga further develop an energy roadmap.

“Tonga relies heavily on external aid from countries such as New Zealand and China, so the students findings can help inform funding applications to implement chosen power systems,” Dr Lapthorn said

The trip, mainly funded by the University’s College of Engineering, was part of developing its reputation to engage in projects that are useful for businesses, communities and natural environments.

The university has led a number of projects in Tonga over the past few years that resulted in the installation of solar systems on six school rooftops to help reduce expensive diesel fuel power bills.